It has long been known that textile sheet materials such as woven fabrics, knitted fabrics or non-wovens, can be provided with a fine pile of fibers by first applying a thin coat of an aqueous polymer emulsion which generally contains a thickener and acts as an adhesive, then uniformly applying the fibers onto the emulsion coat, usually in such a way that one end of each fiber sticks in the emulsion coat, and then drying the material. Fibers which may be used for flocking are above all of viscose, cellulose or synthetic, fiber-forming polyamides which, as in the case of polyhexamethylene adipamide and polycaprolactam, contain recurring -NH- groups as constituents of their chain molecules. The fibers are generally applied electrostatically, for which purpose they are accelerated, in an electric field, toward the adhesive coat and virtually shot into the latter. The fibers can also be applied mechanically, for example by means of a vibrating screen or by blowing in a stream of air, but this gives felt-like flock coatings.
However, these conventional flocking processes require that the adhesive employed should be a polymer emulsion of relatively high viscosity to prevent excessive penetration of the adhesive into the textile. This presents difficulties in applying, and feeding, the emulsion and furthermore the hand of the flocked products obtained by this process is in most cases insufficiently textile-like.